Keyword: sextupole
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MOPGW008 Transparent Injection for ESRF-EBS injection, kicker, SRF, power-supply 78
 
  • S.M. White, N. Carmignani, M. Dubrulle, M. Morati, P. Raimondi
    ESRF, Grenoble, France
  
  The commissioning of the ESRF-EBS storage ring will start in December 2019 ultimately providing a horizontal emittance of 130 pm, 30 times lower than the present one. Due to the reduced beam lifetime top-up operation will be required for all operating modes. Transparent injection, i.e. with negligible perturbations on the stored beam, is necessary to allow continuous data acquisition for beam lines experiments. Several options have been considered at ESRF to reduce these perturbations down to a fraction of the rms beam size: i) new kickers power supplies with slow ramping time to facilitate active compensation are under development and will be implemented in the coming years ii) in parallel, long term solutions using non-linear kickers and longitudinal on-axis injection have been investigated.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW008  
About • paper received ※ 13 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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MOPGW022 Achromatic Isochronous Mode of the ESR at GSI optics, experiment, detector, emittance 124
 
  • S.A. Litvinov, M. Steck
    GSI, Darmstadt, Germany
  
  The isochronous optics of the ESR is a unique ion-optical setting in which the ring is operated as a Time-of-Flight Mass-Spectrometer and is used for direct mass measurements of short-lived exotic nuclei. The present isochronous optics had been performed only making a negative dispersion in the straight sections of the ESR of about -7 m. This negative dispersion makes the injection into the ESR very complicated and strict the transmission of the ions in the ring. Moreover, the non-achromatism of the ESR brings a supplementary uncorrectable first-order transverse contribution to the revolution time. In order to make the ESR achromatic, to improve injection and the isochronicity a new achromatic isochronous optics has been calculated and will be presented here in details.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW022  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPGW045 A Fast Method for Multi-Objective Nonlinear Dynamics Optimization of a Storage Ring SRF, storage-ring, lattice, dynamic-aperture 190
 
  • J.J. Tan, Z.H. Bai, W. Li, L. Wang, P.H. Yang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  
  Multi-objective evolutionary algorithms (MOEAs), including multi-objective genetic algorithm and particle swarm optimization algorithm, have been widely applied in the nonlinear dynamics optimization of storage ring light sources. In the optimization, the direct tracking of objectives, which are, for example, dynamic aperture (DA) and momentum aperture, is very time-consuming. We noticed that there is some positive correlation between on- and off-momentum nonlinear dynamics performances, which can be used to reduce the computation time when applying MOEAs. In this paper, a fast method is proposed, in which a strategy is introduced to speed up the process of optimizing nonlinear dynamics using MOEAs. Taking the SSRF storage ring as an example, on- and off-momentum DAs are optimized using MOEAs with and without the fast strategy, and then a comparison is made to demonstrate the fast method.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW045  
About • paper received ※ 15 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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MOPGW090 Alignment of a Magnetic Lattice Based on Particle Tracking alignment, lattice, optics, controls 324
 
  • K.P. Nesteruk, C. Calzolaio, J.M. Schippers
    PSI, Villigen PSI, Switzerland
  
  In calculations based on particle tracking in 3D magnetic field maps alignment of the components of a magnetic lattice is essential to obtain desired properties of beam optics. In this contribution we propose a method to control and correct misalignments during the process of the beam optics design. These misalignments would result from overlapping fringe fields of different field maps. The 3D field maps are obtained from the software for electromagnetic calculations OPERA. The full 3D map is saved in the tracking coordinate system and a ROOT (An Object Oriented Data Analysis Framework) ntuple is then created for analysis. The trajectory of the reference particle is calculated by means of OPAL - open source code developed at the Paul Scherrer Institut (PSI). The transverse magnetic field profiles allow possible misalignments to be precisely determined and the corresponding corrections to be calculated. Moreover, the multipole content in discrete locations along the lattice can be controlled by performing a polynomial fit, which calculates the magnetic field harmonics with respect to the reference track. This method was used at PSI for a design of a model of the magnetic lattice for a superconducting gantry for proton therapy with a large momentum acceptance.
*An Object Oriented Data Analysis Framework - http://root.cern.ch 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW090  
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPGW096 Beam Dynamics in MBA Lattices with Different Chromaticity Correction Schemes lattice, emittance, betatron, storage-ring 346
 
  • L. Hoummi, J. Resta-López, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • L. Hoummi, J. Resta-López, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • A. Loulergue, R. Nagaoka
    SOLEIL, Gif-sur-Yvette, France
  
  Ultra-low emittance lattices are being studied for the future upgrade of the 2.75 GeV SOLEIL storage ring. The candidate baseline lattice was inspired by the ESRF-EBS-type Multi-Bend-Achromat (MBA) lattice, introducing a (-I) transformation to compensate the nonlinear impact of sextupoles thanks to the lattice symmetry and tight control of the betatron phase advance between sextupoles. Whilst the final performance is still being optimized, other types of lattices are being considered for SOLEIL: This includes the so-called High-Order Achromat (HOA) lattice. Though the (-I) scheme provides a large on-momentum transverse dynamic aperture in 4D, its off-momentum performance is rather limited. 6D studies reveal intrinsic off-momentum transverse oscillations which are likely to result from a nonlinear increase in path length. This contribution presents the effects from the inhomogeneous sextupole distribution in the (-I) scheme and compares them with the HOA lattice.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW096  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPGW097 SOLEIL Storage Ring Upgrade Performance in Presence of Lattice Imperfections lattice, quadrupole, closed-orbit, dipole 350
 
  • A. Vivoli, A. Bence, P. Brunelle, A. Gamelin, L. Hoummi, A. Loulergue, L.S. Nadolski, R. Nagaoka, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette, France
  
  The design for the upgrade of the SOLEIL third generation light source is progressing. At the present stage, different lattices are evaluated as possible candidates for the storage ring upgrade and an important factor for the comparison of their performances is the robustness against lattice imperfections. The strategy for this study consists in defining a set of misalignments of the lattice elements and field errors of the magnets that are expected to be attained after the commissioning, applying them to the lattice models and correcting them using response matrix based techniques. A dedicated algorithm was developed in Accelerator Toolbox in order to accomplish this procedure and compare the different lattices. In this paper the results of this study at the current state are presented, including the considered lattice imperfections, the correction method applied and the final performance of the lattices.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW097  
About • paper received ※ 14 May 2019       paper accepted ※ 17 May 2019       issue date ※ 21 June 2019  
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MOPGW100 Bypass Design for Testing Optical Stochastic Cooling at the Cornell Electron Storage Ring (CESR) optics, radiation, wiggler, damping 360
 
  • W.F. Bergan, M.B. Andorf, M.P. Ehrlichman, V. Khachatryan, D.L. Rubin, S. Wang
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  Funding: NSF-1734189 DGE-1650441
Optical Stochastic Cooling (OSC) is a promising method for cooling very dense stored particle beams through the interference of radiation created in an upstream ’pickup’ wiggler and a downstream ’kicker’ wiggler. By correlating a particle’s path length via a bypass between the two wigglers with its betatron coordinates in the pickup, the particle will receive a kick in energy which, through coupling introduced by non-zero horizontal dispersion in the kicker, can reduce its betatron amplitude, thus cooling the beam. A proof-of-principle test of this technique is being planned at the Cornell Electron Storage Ring (CESR). In addition to maintaining standard requirements such as a large dynamic aperture and acceptable lattice functions throughout the ring, the design of the bypass is guided by the mutually competing goals of maximizing the cooling rate while maintaining a sufficiently large cooling acceptance with properly-corrected nonlinearities. We present a design of such a bypass and ring optics so as to best achieve these objectives. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW100  
About • paper received ※ 14 May 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
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MOPGW107 Study of Integrable and Quasi-Integrable Sextupole Lattice resonance, focusing, lattice, optics 371
 
  • L. Gupta, Y.K. Kim
    University of Chicago, Chicago, Illinois, USA
  • S. Baturin
    Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA
  • S. Nagaitsev
    Fermilab, Batavia, Illinois, USA
  
  Funding: Funded through Center for Bright Beams, NSF award PHY-1549132
In order to maximize beam lifetime in circular particle accelerators, the nonlinear beam optics are optimized to maximize the dynamic aperture of the beam. The dynamic aperture (DA), which is a 6-D phase space volume of stable trajectories, depends on the strength of the nonlinearities in the machine, and is calculated via particle tracking. Current DA optimization processes include multi-objective genetic algorithm optimizers, and relies on minimizing the magnitudes of resonance driving terms (RDT), which are calculated from the nonlinear contribution to the one-turn-map. The process of searching through the parameter space for an ideal combination that maximizes DA is computationally strenuous. By setting up the sextupole channel such that it is resembles a symplectic integrator of a smooth Hamiltonian, with only a few sextupoles we are able to closely reproduce phase space trajectories of a smooth Hamiltonian up to the hyperbolic point. No chaos and resonances are observed if phase advance per one sextupole magnet in the channel does not exceed ~0.12x2 pi. Therefore, an important property of the suggested approach is the intrinsic elimination of the resonances, and minimization of corresponding RDTs. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW107  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPGW115 A Cross-Cell Interleaved Nonlinear Lattice for Potential NSLS-II Upgrade lattice, emittance, optics, dynamic-aperture 393
 
  • Y. Li, A. He, B.N. Kosciuk, T.V. Shaftan, V.V. Smaluk
    BNL, Upton, Long Island, New York, USA
  • Z.H. Bai, L. Wang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  
  An interleaved sextupole scheme using cross-cell betatron phase cancellation technique is adopted as a candidate for the future NSLS-II upgrade lattice. The lattice uses as many NSLS-II installed magnets as possible, including 30 dipoles, to compose a triple bend achromat lattice. A 300 pm.rad horizontal beam emittance is achieved. The emittance can be further reduced to around 200 pm rad with damping wigglers. Various design concepts used in modern 4th-generation light sources, such as adopting longitudinal gradient dipoles and anti-bend scheme, are incorporated into the design as well. The betatron phase-advance between sextupoles is designed to have a cross-cell interleaving cancellation pattern in the transverse planes. The dynamic aperture is big enough for the conventional off-axis top-off injection. At the same time, a large energy acceptance looks promising to ensure a sufficiently long beam lifetime.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW115  
About • paper received ※ 12 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPMP034 Tuning Studies of the CLIC 380 Gev Final Focus System luminosity, alignment, collider, linear-collider 512
 
  • J. Ögren, A. Latina, D. Schulte, R. Tomás
    CERN, Meyrin, Switzerland
  
  We present tuning studies of the Compact Linear Collider final-focus system under static imperfections including transverse misalignments, roll errors and magnetic strength errors. The tuning procedure consists of beam-based alignment for correcting the linear part of the system followed by sextupole pre-alignment and use of multipole tuning knobs. The sextupole pre-alignment is very robust and allows the tuning time to be greatly reduced.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP034  
About • paper received ※ 06 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPMP046 Mitigation of Persistent Current Effects in the RHIC Superconducting Magnets dipole, quadrupole, injection, betatron 548
 
  • C. Liu, D. Bruno, A. Marusic, M.G. Minty, P. Thieberger
    BNL, Upton, Long Island, New York, USA
  • X. Wang
    LBNL, Berkeley, California, USA
  
  Funding: This work was supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Persistent currents in superconducting magnet introduce errors in the magnetic fields especially at low operating currents. In addition, their decay cause magnetic field variations therefore drifts of beam orbits, tunes and chromaticities. To reduce field errors and suppress magnetic field variations, new magnetic cycles were proposed for low energy beam operation at RHIC. In the new magnetic cycles, the magnet current oscillates around the operating current with diminishing amplitude a few times before it settles. The new magnetic cycle has been demonstrated experimentally to reduce field errors and the amplitude of magnetic field variations significantly and is essential for the ongoing RHIC Beam Energy Scan II (BES-II) program. This article will present beam-based experimental studies of the persistent current effects with the new magnetic cycle, and discuss its application in RHIC and accelerators based on superconducting magnet in general. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP046  
About • paper received ※ 30 April 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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MOPRB001 Low Emittance Tuning of FCC-ee emittance, coupling, lattice, quadrupole 574
 
  • T.K. Charles
    The University of Melbourne, Melbourne, Victoria, Australia
  • S. Aumon, B.J. Holzer, F. Zimmermann
    CERN, Geneva, Switzerland
  • K. Oide
    KEK, Ibaraki, Japan
  
  The FCC-ee project studies the design of a future 100 km e+/e− circular collider for precision studies and rare decay observations in the range of 90 to 350 GeV center of mass energy with luminosities in the order of 1036 cm-2s-1. In order to reach these luminosity requirements, extreme focusing is needed in the interaction regions. For the Z energy (45.6 GeV) lattice, the maximum beta value is 8322 m, and the vertical beta function is 0.8 mm at the IP. These aspects of the FCC-ee lattice make it particularly susceptible to misalignments and field errors, and therefore present an appreciable challenge for emittance tuning. A challenging correction scheme is proposed to reduce the coupling and the vertical emittance. We describe a comprehensive correction strategy used for the low emittance tuning. The strategy includes special programs, that had been developed to optimise the lattice based on Dispersion Free Steering, linear coupling compensation based on Resonant Driving Terms and beta beat correction utilising response matrices. Thousands of misalignment and field error random seeds were introduced in MADX simulations and the final corrected lattices are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB001  
About • paper received ※ 09 April 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
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MOPRB005 Study of Higher-Order Achromat Lattice as an Alternative Option for the SOLEIL Storage Ring Upgrade lattice, storage-ring, octupole, injection 586
 
  • R. Nagaoka, A. Bence, P. Brunelle, L. Hoummi, A. Loulergue, A. Nadji, L.S. Nadolski, M.-A. Tordeux, A. Vivoli
    SOLEIL, Gif-sur-Yvette, France
  • A. Gamelin
    LAL, Orsay, France
  
  A ring composed of 20 symmetrical 7BA cells in which of a pair of chromaticity correcting sextupoles placed around horizontal dispersion bumps à la ESRF-EBS was developed as a baseline lattice for the SOLEIL storage ring upgrade (presented at IPAC2018). The strict phase relation between the two dispersion bumps provides an efficient way of optimizing the (on-momentum) nonlinear optics with a limited number of sextupoles. As an alternative, a scheme known as Higher-Order Achromat (HOA) develops a MBA (Multi-Bend Achromat) lattice where chromaticity correcting sextupoles are distributed in each M unit cell with a strict phase relation cell-wise such as to cancel basic geometric and chromatic resonance driving terms. The beam dynamics in a 20-fold 7BA HOA ring is compared with those of the baseline lattice, with focus on off-momentum properties such as Touschek lifetime, which are important for medium energy rings like SOLEIL. The robustness against errors, the reduction of the ring symmetry by introducing 4 longer straight sections, as well as a horizontal dispersion bump to cope with longitudinal on-axis injection scheme are also presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB005  
About • paper received ※ 22 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB032 Interaction Section Lattice Design for a STCF Project betatron, interaction-region, quadrupole, luminosity 646
 
  • W.W. Gao, J.Q. Lan
    Fujian University of Technology, Fuzhou, People’s Republic of China
  • Q. Luo
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  
  The Super Tau-Charm Factory (STCF) planning in China is characterized with high luminosity, wide energy range and high longitudinal polarized electron beam. In order to achieve high luminosity, this project will adopt the recently proposed collision scheme based on Large Piwinski angle and Crab Waist. In this paper, a preliminary lattice design of interaction region meeting the above collision scheme is described.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB032  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPTS004 2nd Order Optics Symmetrisation through Off-Energy Orbit Response Matrix Analysis optics, storage-ring, lattice, alignment 841
 
  • D.K. Olsson, Å. Andersson, M. Sjöström
    MAX IV Laboratory, Lund University, Lund, Sweden
  
  The MAX IV 3 GeV storage ring lattice contains several strong sextupoles. In order to achieve nominal lattice performance it is important to be able to characterise and correct the higher order magnets and optics of the lattice. This has been done through the analysis of the Off-Energy Response Matrix (OEORM). Its approximate linearity in sextupole strength has been utilised to identify sextupole errors, as well as symmetrise the 2nd order optics. The symmetrisation was able to correct chromaticity, and increase horizontal acceptance by 50 %, compared to magnet settings based solely on rotating coil measurements. An approximate decrease of 10 % in vertical acceptance was detected. This work was inspired by similar investigations at ESRF.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS004  
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPTS010 Simulation of the Guide Field Flipping Procedure for the Frequency Domain Method GUI, lattice, simulation, dipole 858
 
  • A.E. Aksentyev
    FZJ, Jülich, Germany
  • A.E. Aksentyev
    MEPhI, Moscow, Russia
  • A.E. Aksentyev, V. Senichev
    RAS/INR, Moscow, Russia
  
  The spin vector of a particle injected into a perfectly aligned storage ring precesses about the vertically-orientated guide field. In the presence of an Electric Dipole Moment (EDM), the spin precession axis acquires a proportional radial component. However, in an imperfect ring, rotational magnet misalignments induce a radial component to the spin precession axis, related to the Magnetic Dipole Moment (MDM). In the Frequency Domain Method, [*] this additional precession is dealt with by consecutively injecting the beam in opposite directions, and constructing the EDM estimator as the sum of the clockwise and counter-clockwise vertical plane precession frequencies. Since the radial MDM component changes sign when the magnetic field direction is reversed, it cancels in the sum, leaving only the EDM effect. In order to reproduce the guide field magnitude with precision sufficient for the cancellation of the MDM effect, we propose to calibrate the guide field via the horizontal plane precession frequency. In the present work we describe the algorithm of the field flipping procedure, and do a numerical simulation.
[*] Senichev Y, Aksentev A, Ivanov A, Valetov E. Frequency domain method of the search for the deuteron electric dipole moment in a storage ring with imperfections. arXiv:171106512. 2017 Nov 17. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS010  
About • paper received ※ 08 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPTS012 Spin Decoherence in the Frozen Spin Storage Ring Method of Search for a Particle EDM storage-ring, lattice, simulation, betatron 864
 
  • A.E. Aksentyev
    FZJ, Jülich, Germany
  • A.E. Aksentyev
    MEPhI, Moscow, Russia
  • A.E. Aksentyev, V. Senichev
    RAS/INR, Moscow, Russia
  
  Spin coherence refers to a measure of preservation of polarization in an initially polarized beam. The spin vector of a particle injected into a storage ring starts to precess about the vertical magnetic field vector in accordance with the Thomas-BMT equation. The precession frequency is dependent on the equilibrium-level energy, which differs across the beam particles. This does not pose a problem when the initial polarization is vertical; however, the Frozen Spin Storage Ring EDM search method [*] requires beam polarization along the momentum vector, i.e., in the horizontal plane. In the present work we analyze the source of decoherence, and investigate the way it can be suppressed in the horizontal plane in a perfectly aligned ring by means of sextupole fields. We also consider the case of an imperfect ring: transference of decoherence into the vertical plane induced by vertical plane spin precession, and the effect of sextupole fields.
* D. Anastassopoulos et al. AGS Proposal: Search for a permanent electric dipole moment of the deuteron nucleus at the 10 −29 e · cm level. BNL report, 2008. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS012  
About • paper received ※ 08 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPTS017 Status of Operation With Negative Momentum Compaction at KARA optics, operation, injection, quadrupole 878
 
  • P. Schreiber, T. Boltz, M. Brosi, B. Härer, A. Mochihashi, A.-S. Müller, A.I. Papash, M. Schuh
    KIT, Karlsruhe, Germany
  
  Funding: We are supported by the DFG-funded ’Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology’ and European Union’s Horizon 2020 research and innovation programme (No 730871)
For future synchrotron light source development novel operation modes are under investigation. At the Karlsruhe Research Accelerator (KARA) an optics with negative momentum compaction has been proposed, which is currently under commissioning. In this context, the collective effects expected in this regime are studied with an initial focus on the head-tail instability and the micro-bunching instability resulting from CSR self-interaction. In this contribution, we will present the proposed optics and the status of implementation for operation in the negative momentum compaction regime as well as a preliminary discussion of expected collective effects. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS017  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPTS090 Beam-Based Measurement of the Skew-Sextupolar Component of the Radio Frequency Field of a HL-LHC-Type Crab-Cavity cavity, betatron, damping, experiment 1066
 
  • M. Carlà, A. Alekou, H. Bartosik, L.R. Carver
    CERN, Geneva, Switzerland
  
  Two High Luminosity Large Hadron Collider (LHC) type crab-cavities have been installed in the CERN SPS for testing purposes. An attempt to characterize the skew-sextupolar component of the radio frequency field of the crab-cavity (a3) has been carried out by means of beam-based techniques using turn-by-turn monitoring of the betatron motion. The skew nature of a3 couples the horizontal and vertical betatron motions through a non-linear term. Therefore by exciting the horizontal betatron motion it was possible to observe a spectral line in the vertical beam motion driven by the non-linear coupling at the characteristic frequency 2Qx. A measurement of the magnitude of a3 was thus obtained by characterizing amplitude and phase of such line. The results of the measurements are discussed here.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS090  
About • paper received ※ 06 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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MOPTS102 Linear and Non-Linear Optics Measurements in PS using Turn-by-Turn BPM Data injection, optics, coupling, betatron 1114
 
  • P.K. Skowroński, M. Giovannozzi, A. Huschauer
    CERN, Meyrin, Switzerland
  
  For the first time, the optics of the CERN Proton Synchrotron (PS) was measured using turn-by-turn BPM data of forced betatron oscillations excited with an AC dipole. We report results of phase advance and beta beating measurements. Linear coupling was globally minimized along the machine by measuring and correcting coupling resonance driving terms. Finally, non-linear properties of the ring were probed looking at third and fourth order resonance driving terms and amplitude detuning.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS102  
About • paper received ※ 07 May 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
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TUYPLM3 Status of the MAX IV Accelerators storage-ring, electron, linac, vacuum 1185
 
  • P.F. Tavares, E. Al-Dmour, Å. Andersson, J. Breunlin, F.J. Cullinan, E. Mansten, S. Molloy, D.K. Olsson, D. Olsson, M. Sjöström, S. Thorin
    MAX IV Laboratory, Lund University, Lund, Sweden
  
  The MAX IV facility in Lund, Sweden, consists of three electron accelerators and their respective synchrotron radiation beamlines: a 3 GeV ring, which is the first implementation worldwide of a multi-bend achromat lattice, a 1.5 GeV ring optimized for soft X-Rays and UV radiation production and a 3 GeV linear accelerator that acts as a full-energy injector into both rings and provides electron pulses as short as 100 fs that produce X-rays by spontaneous emission in the undulators of the short-pulse facility (SPF). In this paper, we review the latest achieved accelerator performance and operational results.  
slides icon Slides TUYPLM3 [9.108 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUYPLM3  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPGW018 PETRA IV Study with Non-Interleaved Sextupole Scheme lattice, emittance, storage-ring, optics 1430
 
  • H.C. Chao, R. Brinkmann, X.N. Gavaldà
    DESY, Hamburg, Germany
  
  This study is an attempt to design PETRA IV storage ring, which is an upgrade from PETRA III toward diffraction-limit synchrotron light source, based on the non-interleaved sextupole scheme. The lattice is constructed by mixing different types of cells. There are two basic building blocks. The double minus identity (DMI) cell dedicated for the chromaticity correction with non-interleaved sextupoles is tightly built up, while the combined function FODO cell with dispersion suppressors provides straights with small beta functions ideally for undulators. In addition, the hybrid section including a 10-m long super insertion device (ID) is custom-made to adapt to DESY’s current site plan. The beam dynamic behaviors are simulated and discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW018  
About • paper received ※ 18 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPGW020 Non-Linear Features of the cSTART Project storage-ring, quadrupole, lattice, injection 1437
 
  • B. Härer, E. Bründermann, A.B. Kaiser, A.-S. Müller, A.I. Papash, R. Ruprecht, J.M. Schaefer, M. Schuh
    KIT, Karlsruhe, Germany
  
  The compact storage ring for accelerator research and technology (cSTART) is being designed and will be realized at the Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT). One important goal of the project is to demonstrate injection and storage of a laser wakefield accelerator (LWFA) beam in a storage ring. As a first stage the compact linear accelerator FLUTE will serve as an injector of 50 MeV bunches to test the ring’s performance. A highly non-linear lattice of DBA-FDF type was studied extensively. The specific features of ring optics are reported. A special transfer line from FLUTE to cSTART including bunch compressor and non-linear elements is presented that maintains the ultra-short bunch length of FLUTE.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW020  
About • paper received ※ 13 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPGW037 Systematic Measurements of the Coherent THz Spectra by Magnetic Bunch Compression at the Compact ERL optics, electron, radiation, linac 1486
 
  • M. Shimada, Y. Honda, R. Kato, T. Miyajima, N. Nakamura, T. Obina, T. Uchiyama
    KEK, Ibaraki, Japan
  • T. Hotei
    Sokendai, Ibaraki, Japan
  
  Short electron bunch beam is one of the key elements of a Free Electron Laser (FEL) or intense THz coherent light source. The Energy Recovery Linac (ERL) has the strong advantage of operation of such an electron bunch at high repetition rate and is expected to increase the photon flux. At the Compact ERL in KEK site, we have demonstrated the magnetic bunch compression at the 180-degree return arc and measured the THz spectra of the Coherent Transition Radiation (CTR). This paper reports the revamped THz beamline and the improvement of the beam tuning as well as the systematic measurements of the THz spectra by magnetic bunch compression.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW037  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPGW041 Super-Period Locally Symmetric Lattices for Designing Diffraction-Limited Storage Rings lattice, storage-ring, emittance, quadrupole 1498
 
  • Z.H. Bai, W. Li, G. Liu, L. Wang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  • Y. Li
    BNL, Upton, Long Island, New York, USA
  
  To achieve better nonlinear dynamics performance for a diffraction-limited storage ring, previously we proposed a locally symmetric multi-bend-achromat (MBA) lattice concept, where beta functions are locally symmetric about two mirror planes of each lattice cell. To have both high-beta long straight sections for beam injection and low-beta ones for higher brightness of insertion device radiation, many storage ring light sources use super-period lattices. The locally symmetric MBA lattice can be naturally extended to the super-period case. In the super-period locally symmetric (SP-LS) lattice, many nonlinear dynamics effects can be effectively cancelled out within one super-period lattice cell, and also there are many knobs to be used for further nonlinear optimization. As examples, two SP-LS lattices have been designed towards diffraction-limited emittances.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW041  
About • paper received ※ 20 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPGW054 Design of a Hybrid Seven-Bend-Achromat Lattice for a High-Energy Diffraction-Limited Storage Ring Using a New Optimization Method lattice, linear-dynamics, emittance, optics 1528
 
  • P.H. Yang, Z.H. Bai, J.J. Tan, L. Wang, J.H. Xu
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  
  Recently, we proposed a new optimization method, with nonlinear dynamics indicators considered in the linear optics design, for designing hybrid multi-bend-achromat (MBA) lattices. With this method, two hybrid MBA lattices for medium-low-energy diffraction limited storage rings (DLSRs) have been designed, showing remarkable effectiveness in improving nonlinear dynamic performance. In this paper, we will apply this optimization method to the design of a hybrid 7BA lattice for a 6 GeV DLSR with the same circumference as that of HEPS. In the design, the strengths and arrangement of magnets of this lattice also meet the engineering requirement for HEPS. The designed lattice has a natural emittance of 34 pm·rad. The nonlinear dynamic performance is satisfactory, with a dynamic aperture of about 6 mm and 3 mm in the horizontal and vertical directions, respectively, and a dynamic momentum aperture of larger than 5%, which also shows the power of our optimization method.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW054  
About • paper received ※ 14 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPGW055 Comparison of Optimization Methods for Hybrid Seven-Bend-Achromat Lattice Design lattice, linear-dynamics, optics, emittance 1532
 
  • P.H. Yang, Z.H. Bai, J.J. Tan, L. Wang, J.H. Xu
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  
  Generally, for a hybrid multi-bend-achromat (MBA) lattice with fixed linear optics, there is little potential to further optimize the nonlinear dynamics due to limited free knobs. To obtain a hybrid MBA lattice with better nonlinear dynamics performance, it is better to consider some indicators of nonlinear dynamics as objective functions in designing the linear optics using an optimization algorithm. In this paper, integral strengths of sextupoles and natural chromaticities are used as the nonlinear dynamics indicators, and different optimization methods with both or either of the two indicators are carried out and compared. As an example, a hybrid 7BA lattice with an energy of 2.4 GeV is designed towards an emittance of less than 70 pm·rad.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW055  
About • paper received ※ 18 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPGW056 Comparison of Constrained Optimization Methods for Designing a Multi-Bend Achromat Lattice lattice, emittance, storage-ring, linear-dynamics 1535
 
  • J.H. Xu, Z.H. Bai, W. Li, P.H. Yang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  
  In the design of a multi-bend achromat (MBA) lattice for a diffraction-limited storage ring, there are usually many magnet parameters to be optimized and some stringent constraints to be satisfied. For example, to cancel out nonlinear dynamics effects, the phase advances between some sections are generally required to be set to certain values in the lattice design. For better designing a MBA lattice using an evolutionary algorithm, the handling of constraints will be important, because it is very hard to satisfy the constraints for most or even all of solutions in the early generations of the algorithm. This paper will first describe some methods for handling constraints, which are then applied to designing a hybrid 7BA lattice. The comparison of these methods shows that better lattice solutions can be obtained by including constraints into objective functions.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW056  
About • paper received ※ 23 April 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
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TUPGW057 A Ten-Bend Achromat Lattice with Interleaved Dispersion Bumps for a Diffraction-Limited Storage Ring lattice, emittance, storage-ring, quadrupole 1538
 
  • P.H. Yang, Z.H. Bai, J.J. Tan, L. Wang, J.H. Xu
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  
  Recently, a multi-bend achromat (MBA) lattice concept, called the MBA with interleaved dispersion bumps (IDB-MBA), was proposed to design the HALS storage ring, which presented better performance of both on- and off-momentum nonlinear dynamics. Since the beam emittance scales inversely with the third power of the number of bending magnets, in this paper we will study a new IDB-MBA lattice with more bending magnets. It is feasible to satisfy the requirement of the IDB-MBA concept in a 10BA lattice, and an IDB-10BA lattice is then designed for a storage ring light source with an energy of 2.4 GeV. The designed lattice has an ultra-low natural emittance of 81 pm·rad, and a dynamic aperture of about 6 mm and a large dynamic momentum aperture of 6% are achieved.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW057  
About • paper received ※ 24 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPGW064 Trials of Beam-Based Sextupole Calibration through 2nd Order Dispersion storage-ring, optics, lattice, ECR 1551
 
  • D.K. Olsson, Å. Andersson, M. Sjöström
    MAX IV Laboratory, Lund University, Lund, Sweden
  
  In order to achieve nominal performance in terms of the dynamic aperture and lifetime of a storage ring, it is important to be able to characterise and correct its second order optics. At the MAX IV 3 GeV storage ring in Lund, Sweden, the linearity of the 2nd order dispersion with chromatic sextupole field strengths has been utilised to investigate the sextupole circuits. The beating induced in the 2nd order dispersion when reducing the strength of a sextupole magnet can be compared to the beating in simulations. From this a beam-based sextupole calibration curve can be found. This work was inspired by similar work done at ESRF.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW064  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPGW077 Impact of the DIAD Wiggler and ’Missing-sextupole’ Optics on the Diamond Storage Ring wiggler, storage-ring, optics, operation 1581
 
  • I.P.S. Martin, R. Bartolini, B. Singh
    DLS, Oxfordshire, United Kingdom
  
  In order to generate space for a short, out-of-vacuum multipole wiggler for the DIAD beamline, a single sextupole was removed from one of the DBA arcs in the Diamond Storage Ring during June 2018. The removal of this sextupole presented a number of challenges to the operation of the storage ring, requiring a re-optimisation of the remaining sextupole strengths*, a change in tune-point and modification of the orbit and coupling correction schemes. In this paper we describe the implementation of these changes, and provide an assessment of the impact that the installed wiggler has made on the storage ring parameters.
* B. Singh et al. ’Studies to Install a Multipole Wiggler by Removing a Chromatic Sextupole in Diamond Storage Ring’, Proc. IPAC 2016, Busan, Korea, paper THPMR050, (2016)
 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW077  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPGW080 Alternative Lattice Design for Diamond-II lattice, emittance, dipole, optics 1593
 
  • M. Korostelev
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • B. Singh
    DLS, Oxfordshire, United Kingdom
  
  Plans for upgrade of the Diamond Light Source aim to reduce beam emittance by a factor of 20 or better. This is motivated by demand for photon flux with significantly high brightness and transverse coherence. The baseline lattice design for the Diamond-II upgrade has been recently proposed, however alternative design are under investigation to reduce the emittance even further. This paper presents a new lattice design based on implementation of bending magnets with transverse field gradient only.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW080  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPGW090 Experimental Tests of the Automated APS-U Commissioning Algorithm at APS MMI, lattice, simulation, closed-orbit 1615
 
  • V. Sajaev
    ANL, Argonne, Illinois, USA
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02- 06CH11357
APS Upgrade (APS-U) will feature hybrid seven-bend achromat lattice with very strong focusing elements and relatively small vacuum chamber aperture. Achieving design lattice parameters during commissioning will need to be accomplished quickly in order to minimize dark time for APS users. The paper will describe the automated start-to-end lattice commissioning algorithm starting with the first-turn trajectory correction and ending with the lattice correction. It will then show simulation results of the APS-U commissioning, and finally present results of the experimental tests of the commissioning at the existing APS. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW090  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPGW095 Progress on a Novel 7BA Lattice for a 196-m Circumference Diffraction-Limited Soft X-Ray Storage Ring lattice, emittance, optics, storage-ring 1635
 
  • S.C. Leemann, F. Sannibale
    LBNL, Berkeley, USA
  • M. Aiba, A. Streun
    PSI, Villigen PSI, Switzerland
  • J. Bengtsson
    DLS, Oxfordshire, United Kingdom
  • L.O. Dallin
    CLS, Saskatoon, Saskatchewan, Canada
  
  Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract No. DEAC02-05CH11231.
The ALS Upgrade to a diffraction-limited soft x-ray storage ring calls for ultralow emittance in a very limited circumference. In this paper we report on progress with a lattice based on a 7BA with distributed chromatic correction. This lattice relies heavily on longitudinal gradient bends and reverse bending in order to suppress the emittance, so that, despite having only seven bends, ultralow emittance can be achieved in addition to large dynamic aperture and momentum acceptance. An initial alternate 7BA lattice has been revised to relax magnet requirements as well as further increase off-energy performance and resilience to machine imperfections. We now demonstrate ±2.5 mm dynamic aperture including errors and calculate the effect of IBS to show that this lattice achieves 6 hours Touschek lifetime (at 500 mA, including errors) and a brightness of roughly 3x1021 ph/s/mm2/mrad2/0.1%BW at 1 keV. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW095  
About • paper received ※ 14 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPGW099 Superconducting Crab Cavity Options for Short X-Ray Pulse Generation in SPEAR3 cavity, GUI, impedance, HOM 1647
 
  • F. Toufexis, V.A. Dolgashev, X. Huang, Z. Li
    SLAC, Menlo Park, California, USA
  
  Funding: This project was funded by U.S. Department of Energy under Contract No. DE-AC02-76SF00515.
We are exploring methods to generate short X-ray pulses in SPEAR3 on the order of 1 ps to enable studying ultrafast processes in materials. We are developing a 2-frequency crab cavity scheme with two sets of crab cavities* at the 6th and 6.5th harmonics of the 476 MHz ring RF frequency. In previous work we studied a normal conducting crab cavity for SPEAR3**. In this work we explored two superconducting cavity options: a traditional elliptical cavity and the Quasi-waveguide Resonator***. We found that the Quasi-waveguide Resonator cannot meet our field uniformity specifications due to higher order multipole fields. We then optimized a traditional elliptical cavity with the input, Lower Order Modes, and Higher Order Modes couplers following the Argonne Advanced Photon Source design.
* A. Zholents, et al, Nucl. Instrum. Methods Phys. Res., Sect. A, Vol. 425 (1999), p. 385.
** Z. Li, et al, Proceedings of IPAC17.
*** A. Lunin, et al, Proceedings of HOMSC14.
 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW099  
About • paper received ※ 11 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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TUPRB042 Design Study of Nonlinear Energy Chirp Correction Using Sextupole Magnets at the Soft X-Ray Free-Electron Laser Beamline of SACLA FEL, electron, linac, cavity 1782
 
  • K. Togawa, T. Hara, H. Tanaka
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  
  At the x-ray free-electron laser (FEL) facility, SACLA, a soft x-ray FEL beamline (SCSS+) is driven by a dedicated 800-MeV electron accelerator and being operated in parallel with two hard x-ray FEL beamlines. Responding to the demands of short laser pulses from users, a nonlinearity correction system using sextupole magnets is under consideration to obtain shorter electron bunches. Since the frequency of the SCSS+ injector is S-band, the nonlinearity correction of a bunch compression process using a harmonic correction cavity is not so efficient as the SACLA injector, whose frequency of the injector is L-band. Instead of a complex and costly correction cavity system, the sextupole magnets are simply installed in a dispersive section of the first bunch compressor chicane. In this report, we will present the basic design concept and some detail studies of the nonlinear correction.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB042  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPRB105 Realizing Low-Emittance Lattice Solutions With Complex Bends emittance, lattice, dipole, quadrupole 1906
 
  • V.V. Smaluk, T.V. Shaftan
    BNL, Upton, Long Island, New York, USA
  
  Funding: Department of Energy Contract No. DE-SC0012704
A concept of new lattice element called "Complex Bend" is recently proposed at NSLS-­II. Replacing the regular dipoles in the Double­-Bend Achromat lattice by Complex Bends significantly reduces the beam emittance. The first attempt of lattice design for potential NSLS-­II upgrade based on Complex Bend, is described. Compared with the current NSLS­-II lattice, the new solution modifies only three of the six girders per cell. The linear optics has been matched keeping unchanged the lattice parameters at the straight sections, where the light­-generating insertion devices are located. The Complex Bend gradient is limited by 250 T/m assuming possible use of permanent magnets. The lattice provides 65 pm emittance without damping wigglers, use of which results in further decrease of the emittance 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB105  
About • paper received ※ 30 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPTS033 J-PARC RCS: High-Order Field Components Inherent in the Injection Bump Magnets and Their Effects on the Circulating Beam During Multi-Turn Injection injection, resonance, simulation, operation 2009
 
  • H. Hotchi, H. Harada, T. Takayanagi
    JAEA/J-PARC, Tokai-mura, Japan
  
  The J-PARC RCS utilizes four sets of pulsed dipole magnets for the formation of injection orbit bump. The injection bump magnets have a large aspect ratio (gap length/core length), so there are other high-order field components inherent in their magnetic fields in addition to the main dipole component. The high-order field components, which locally exist in the injection section not following the lattice super-periodicity, have a significant influence on the circulating beam during multi-turn injection via the excitation of high-order random betatron resonances. This paper discusses the detailed mechanism of emittance growth and beam loss caused by the high-order field components of the injection bump magnets including its correction scenario on the basis of numerical simulation and experimental results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS033  
About • paper received ※ 18 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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WEYYPLS2 First Experimental Measurements of the Caustic Nature of Trajectories in Bunch Compressors linac, electron, FEL, experiment 2270
 
  • T.K. Charles
    The University of Melbourne, Melbourne, Victoria, Australia
  • J. Björklund Svensson
    Lund University, Lund, Sweden
  • A. Latina
    CERN, Geneva, Switzerland
  • S. Thorin
    MAX IV Laboratory, Lund University, Lund, Sweden
  
  Theoretical advancements describing density perturbations in accelerated charge particle beams, known as caustics, has been recently developed * This proceeding describes the first experimental measurements of the caustic nature of charged particle trajectories in a particle accelerator. Caustics by their nature are discontinuities that result from small continuous perturbations of an input. Under certain conditions, small density modulations will reliably produce striking changes in the corresponding output current profile. These current modulations can shift alone the bunch with varying higher-order longitudinal dispersion. The MAX IV linac double-bend achromats provide the perfect test bed for experimentally verifying how the caustic lines evolve. The natural amplification of small perturbations makes caustics an attractive diagnostic tool, and effective tool for characterise the bunch compressors. This approach also allows us to modify and improve the longitudinal charge profile, removing current spikes or creating tailor shaped current profiles.
* T.K.Charles et. al. Phys. Rev. Accel. Beams 19, 104402 		 
slides icon Slides WEYYPLS2 [5.402 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYYPLS2  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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WEPMP014 Slow Extraction Study by Using Sextupole extraction, synchrotron, resonance, proton 2332
 
  • L. Huang, S. Wang
    IHEP, Beijing, People’s Republic of China
  
  The spill continuously extracted from synchrotron by using resonance sextupoles plays a key role in multidisciplinary application. The intensity of virtual sextupole and the spiral step for the typical synchrotron are obtained theoretically. A customized synchrotron of extraction components placed in dispersion section is designed and the tracking code of slow extraction is developed, thus the theoretical spiral step is comparative studied. To study the beam loss, three layouts of extraction are also designed based on the synchrotron. The result shows that the beam losses at extraction point are different for three cases and it is advantage to beam loss for extraction components placed in dispersion-free straight section.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP014  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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WEPMP035 Model and Measurements of CERN-SPS Slow Extraction Spill Re-Shaping - the Burst Mode Slow Extraction extraction, experiment, operation, simulation 2406
 
  • M. Pari, M.A. Fraser, B. Goddard, V. Kain, L.S. Stoel, F.M. Velotti
    CERN, Geneva, Switzerland
  
  The ENUBET ("Enhanced NeUtrino BEams from kaon Tagging") Project aims at reaching a new level of precision of the short-baseline neutrino cross section measurement by using an instrumented decay tunnel. The North Area (NA) experimental facility of the Super Proton Synchrotron (SPS) offers the required infrastructure for the experiment. A new slow extraction type, consisting of bursts of many consecutive millisecond spills within one macro spill, has been modeled and tested for the ENUBET Project. The burst-mode slow extraction has been tested for the first time at CERN-SPS, and MADX simulations of the process have been developed. In this paper the experimental results obtained during the test campaign are presented along with the results of the quality of the produced spill and comparing it with predictions from simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP035  
About • paper received ※ 12 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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WEPMP045 Higher Multipoles in 3rd Integer Resonance Extraction extraction, octupole, multipole, simulation 2437
 
  • V.P. Nagaslaev
    Fermilab, Batavia, Illinois, USA
  • K.A. Brown
    BNL, Upton, Long Island, New York, USA
  • M. Tomizawa
    KEK, Ibaraki, Japan
  
  The efficiency of slow extraction is becoming a limiting factor, as the demand for delivered beam power is constantly growing. New methods for improving extraction efficiency include folding the extraction separatrix using the higher multipoles. In this report we discuss a simple and effective approach to determine an optimal placement of those multipoles in the storage ring. This allows reduction of the beam losses and therefore, the level of prompt and residual radioactivity in the accelerator components and surrounding buildings by as much as 40% or more. We also explore here manipulating the higher order effects produced in the pure sextupole configurations for the same purpose and demonstrate that similar results can be achieved by only rearranging the sextupole magnets in the lattice.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP045  
About • paper received ※ 10 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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WEPGW101 A New Orbit Feedforward Table Generation Method for Insertion Devices storage-ring, insertion-device, insertion, ISOL 2724
 
  • Y. Hidaka, B.N. Kosciuk, B. Podobedov, J. Rank, T. Tanabe
    BNL, Upton, Long Island, New York, USA
  
  Funding: The study is supported by U.S. DOE under Contract No. DE-SC0012704.
A new method of orbit feedforward (FF) table generation for insertion devices (IDs) is proposed. The main purpose of the orbit FF table is to suppress orbit disturbance around a storage ring, caused by the gap/phase motion of an ID. A conventional procedure is to measure a closed orbit at a reference ID gap/phase state, and another one at a different state, with all types of orbit feedback (FB) systems disabled. Based on the difference orbit, the correction currents for the local ID correctors are estimated to cancel the global orbit distortion. The new method instead utilizes the orbit deviation at the beam position monitors within an ID straight section (ID BPMs) with respect to a dynamically changing orbit that is defined by the orbit at two BPMs bounding the ID straight. Correction currents are determined such that this orbit deviation at the ID BPMs is minimized. Being impervious to transverse kicks external to this bounded region, this measurement can be performed with a global orbit FB system turned on, which could allow parallel table generation for multiple IDs. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW101  
About • paper received ※ 17 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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WEPTS024 Tune Shifts and Optics Modulations in the High Intensity Operation at J-PARC MR space-charge, simulation, betatron, quadrupole 3148
 
  • T.Y. Yasui
    The University of Tokyo, Graduate School of Science, Tokyo, Japan
  • S. Igarashi, T. Koseki, K. Ohmi, Y. Sato, K. Satou
    KEK, Ibaraki, Japan
  
  Funding: This study is supported by the MEXT program "Advanced Leading Graduate Course for Photon Science (ALPS)"
J-PARC Main Ring (MR) is the intensity-frontier proton accelerator. The beam intensity of 2.6×1014 protons per pulse has been achieved for the current user operation. In this high-intensity operation, the tune spread caused by the space-charge is one of the main reasons for beam loss. The modulation of the betatron function and the tune shift were simulated with a PIC algorithm calculation code*. The simulation results showed that the space-charge effects were dominant in small particle action, and the sextupole fields effects were dominant in large particle action. Because sextupole strength is large in MR, sextupole fields induce substantial tune shifts. At the benchmark of the space-charge simulation, the simulation results matched the analytical space-charge calculations performed without sextupoles. It was found that the betatron function was modulated at most 6% by the space-charge effects and at most 8% by the effects of sextupoles in J-PARC MR. These effects to the injection beam optics matching and to the beam aperture will be investigated.
* K. Ohmi et al., "Study of Halo Formation in J-PARC MR", Proceedings of the 22nd Particle Accelerator Conf. (PAC’07), Albuquerque, NM, USA, Jun. 2007, paper THPAN040, pp. 3318-3320. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS024  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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WEPTS033 A High-performance Code for Beam Dynamics Simulation of Synchrotrons simulation, extraction, synchrotron, proton 3170
 
  • H.J. Yao, X. Guan, G.R. Li, P.F. Ma, X.W. Wang, Q. Zhang, S.X. Zheng
    TUB, Beijing, People’s Republic of China
  
  This paper introduces a high-performance code Li-track for beam dynamics simulation of synchrotrons. It is a parallel multi-particle tracking program written entirely in C++ and therefore has a high computational speed. The overall design of Li-track is based on object-oriented mode, and the implemented element model can be easily reused to build different synchrotron lattice. The symplectic integral algorithm is used to ensure there are no physical errors in a long-term simulation. This code has been used for the slow extraction simulation of XiPAF synchrotron and the results will be given in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS033  
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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WEPTS042 Detailed Characterisation of the LEIR Intensity Limitations for a Pb Ion Beam emittance, resonance, simulation, injection 3196
 
  • Á. Saá Hernández, H. Bartosik, N. Biancacci, S. Hirlaender, D. Moreno Garcia, M. Zampetakis
    CERN, Meyrin, Switzerland
  
  The equilibrium emittance of the Pb beam in the CERN Low Energy Ion Ring (LEIR) results from the interplay of electron cooling and heating processes, as intra-beam scattering and space charge. In this paper we present the measurements of the emittance evolution as a function of intensity, working point and resonance excitation, and compare them with the simulations of the heating processes. Optimum settings for normal and skew sextupoles have been found for the compensation of resonances excited by the lattice.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS042  
About • paper received ※ 18 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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WEPTS103 Optimization of a Low-Alpha Lattice for the HLS-II Storage Ring lattice, storage-ring, quadrupole, dynamic-aperture 3360
 
  • S.W. Wang, Y.G. Wang, W. Xu, K. Xuan
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  • J.Y. Li
    IHEP, Beijing, People’s Republic of China
  
  To generate terahertz radiation at HLS-II, a low-alpha lattice scheme is proposed. The new lattice can reduce the bunch length in the storage ring, thus enhancing the coherent synchrotron radiation in the THz region. In this paper, the design and optimization of a low-alpha lattice is reported. The new lattice preserves the symmetry of nominal lattice and reduces the first and second order momentum factor at the cost of increasing maximum beta function and natural emittance. The bunch length is tracked and the result shows that the low-alpha lattice can effectively compress bunches in the storage ring. The performance of this low-alpha lattice can be further studied and improved.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS103  
About • paper received ※ 29 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPRB099 Applications of Dimension-Reduction to Various Accelerator Physics Problems dynamic-aperture, kicker, synchrotron, storage-ring 4060
 
  • W.F. Bergan, I.V. Bazarov, C.J.R. Duncan, D.L. Rubin
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  Funding: DE-SC 0013571 DGE-1650441 OIA-1549132
Particle accelerators contain hundreds of magnets, making dimension-reduction techniques attractive when attempting to tune them. We apply this procedure to two different problems: correcting the orbit in the Cornell synchrotron and maximizing the dynamic aperture in the Cornell Electron Storage Ring (CESR). Cornell’s rapid cycling synchrotron accepts a 200 MeV beam from the linac and accelerates it to 6 GeV for injection into the CESR. ‘Kicker coils’ (dipole correctors) are used to correct for residual fields which would otherwise cause beam loss at the low energies. In such cases, it is usually advisable to measure and correct the orbit. However, one cannot measure the orbit without first getting the beam to circulate a few hundred times, by which point the low-energy orbit would already be mostly corrected. In order to speed up the process of empirical orbit tuning, we form knobs which have the largest effect on the global orbit error, so that the dimensionality of the space which must be searched may be greatly reduced. A small dynamic aperture in CESR will have adverse effects on beam lifetime and injection efficiency, and so ought to be maximized by tuning sextupoles. However, it is often unclear which sextupoles one ought to tune to alleviate the problem. Moreover, once the chromaticity is properly adjusted, it should not be changed. Since we expect resonance driving terms (RDTs) to have a large impact on the dynamic aperture, we develop sextupole knobs which change the RDTs as much as possible while leaving the chromaticity fixed. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB099  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THPTS010 Start of the Series Production for the Cryogenic Magnet Corrector Modules of FAIR dipole, quadrupole, operation, superconducting-magnet 4124
 
  • E.S. Fischer, A. Bleile, V.I. Datskov, V. Marusov, J.P. Meier, P.J. Spiller
    GSI, Darmstadt, Germany
  
  The fast cycling superconducting synchrotron SIS100 has to deliver high intensity beams for the FAIR project at GSI, Darmstadt. The main dipoles will ramp with 4 T/s up to a maximum magnetic field of 1.9 T where the field gradient of the main quadrupole will reach 27.77 T/m. The integral magnetic field length of the horizontal/vertical steerer and of the chromaticity sextupole will provide 0.403/0.41 m and 0.383 m respectively. We present the status of the first magnets test results as well as the overall procedure of production and testing of the complete series of the cryomagnetic corrector modules.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS010  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THPTS015 Design and Manufacturing of the First Multiplet for the Super-FRS at FAIR quadrupole, status, vacuum, alignment 4138
 
  • E.J. Cho, H. Müller, C. Roux, K. Sugita, M. Winkler
    GSI, Darmstadt, Germany
  • A. Borceto, G. Drago, G. Valesi, D. Ventura
    ASG, Genova, Italy
  
  The Super-FRS (Superconducting FRagment Separator) at FAIR is a two-stage in flight separator, which aims to produce rare isotopes of all elements up to Uranium and separate them spatially within a few hundred nanoseconds so that a study of very short lived nuclei can be performed efficiently. In total, it is required to construct 24 dipoles and 170 multipole magnets (quadrupole, sextupole, octupole and steering dipole). Due to the limit of space, the multipole magnets will be arranged as a group (2 ~ 9 magnets) in a common cryostat and they are called as a multiplet. The design challenge of the multiplet lies in a strong iron saturation of the quadrupole leading to disturb the field quality and high design pressure of the He vessel (20 bars). The first multiplet for the Super-FRS is constructed. The magnet column consisting of one quadrupole and one sextupole is cooled in a He vessel filled with up-to 800 liters of liquid He. The both magnets are superferric type and have a large warm bore radius of 190 mm. This paper presents the design overview and the manufacturing status of the first multiplet.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS015  
About • paper received ※ 12 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPTS017 ILSF Ultralow Emittance Storage Ring Magnets dipole, quadrupole, storage-ring, multipole 4142
 
  • F. Saeidi, S. Dastan, J. Rahighi, M. Razazian
    ILSF, Tehran, Iran
  
  Iranian Light Source Facility (ILSF) is a 3 GeV synchro-tron which is in the basic design phase. The ILSF storage ring (SR) is based on a Five-Bend Achromat lattice providing a low horizontal beam emittance of 270 pm-rad. The ILSF storage ring consists of 100 combined di-pole magnets of 2 types, 240 quadrupoles in 5 families and also 320 sextupoles in 6 families. In this paper, we present some design features of the SR magnets and dis-cuss the detailed physical design of these electromagnets including electrical and cooling calculations. Using POISSON and OPERA codes [1,2], pole and yoke geome-try was developed for each magnet  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS017  
About • paper received ※ 30 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPTS018 ILSF Booster Magnets for the New Low Emittance Lattice booster, dipole, quadrupole, multipole 4145
 
  • F. Saeidi, S. Dastan, S. Fatehi, J. Rahighi, M. Razazian
    ILSF, Tehran, Iran
  
  Iranian light source facility is a new 3rd generation light source with a booster which is supposed to work at 150 keV injection energy and guide the electrons to a 3GeV ring. It consists of 50 combined dipole magnets in one type, 50 quadrupoles and 15 sextupoles in one family. Using POISSON and OPERA3D codes[1,2], pole and yoke geometry was designed for each magnet and also cooling and electrical calculations have been done. ILSF has attempted to mechanical design and build prototype magnets which are ongoing at this stage too.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS018  
About • paper received ※ 30 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPTS021 Magnets for Elettra 2.0 quadrupole, optics, ion-effects, lattice 4152
 
  • D. Castronovo, E. Karantzoulis
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  
  After 25 years of faithfully serving the user community with excellent results, Elettra need a major upgrade with a new compact latice that will replace the existing double bend achromat for the reducing of the horizontal emittance and the increasing of the brilliance and coherence of the X-ray beam. This paper report the magnetic design development and optimisations carried out in order to satisfy the layout feasibility and the magnet strengths.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS021  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPTS024 Magnet Developments and Precise Alignment Schemes for SPring-8-II alignment, multipole, lattice, quadrupole 4158
 
  • K. Fukami, T. Aoki, N. Azumi, H. Kimura, S. Matsubara, S. Takano, T. Taniuchi, T. Watanabe, K. Yanagida, C. Zhang
    JASRI, Hyogo, Japan
  • N. Azumi, K. Fukami, H. Kimura, S. Matsui, S. Takano, T. Watanabe
    RIKEN SPring-8 Center, Hyogo, Japan
  • S.I. Inoue, T. Kai, J. Kiuchi
    SES, Hyogo-pref., Japan
  
  The magnet lattice design of the SPring-8 upgrade, SPring-8-II, is a five bend achromat composed of one normal and four longitudinal gradient bending magnets. Permanent magnet has been chosen for both types of the dipoles, and the high gradient multipole magnets are all electromagnets. This presentation will overview the magnet developments and precise alignment schemes for SPring-8-II, focusing specifically on the following features. Temperature insensitive magnetic circuits with a function of fine magnetic field tuning have been developed for the permanent magnet dipoles. Narrow bore multipole magnets with compact coil assemblies have been designed. We optimized the shimming for enough good field regions, and minimized ohmic loss at the coils for suppressing thermal deformation. To improve the accuracy of vibrating wire magnet alignment, practical wire sag distributions have been quantitatively evaluated. In 2018, a test half-cell was constructed by which the feasibilities of the magnets and the overall alignment precisions including the effects of the thermal deformation of magnets, a repeatability of magnet reassembly has been confirmed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS024  
About • paper received ※ 10 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPTS040 Preliminary Design of Mechanical Supports for the Booster of Heps booster, dipole, quadrupole, alignment 4197
 
  • H. Wang, C.H. Li, C. Meng, H. Qu
    IHEP, Beijing, People’s Republic of China
  
  The Booster of High Energy Photon Source (HEPS) is a 454 meters ring with the repeat frequency of 1 Hz. The natural frequency of the magnets and their support as-sembly should be higher than 30 Hz. The alignment re-quirements on quadrupole and sextupole are better than 0.1 mm in x and y direction. This paper will discuss the preliminary design of the mechanical supports in Booster ring, as well as the discussion of finite element analyses results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS040  
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THPTS076 Design and Construction of Sextupole Magnet Prototype for Siam Photon Source II Project quadrupole, software, simulation, multipole 4295
 
  • S. Prawanta, B. Boonwanna, P. Klysubun, A. Kwankasem, S. Pongampai, V. Sooksrimuang, P. Sudmuang, P. Sunwong
    SLRI, Nakhon Ratchasima, Thailand
  
  Siam Photon Source II (SPS-II) project in Thailand is the third-generation synchrotron light source. The lattice of the 3 GeV electron storage ring has been designed, consisting of 14 Double Triple Bend Achromat (DTBA) cells with the total circumference of 321.3 m. The storage ring lattice includes 56 bending magnets, 28 combined dipole and quadrupole magnets, 224 quadrupole magnets and 84 multifunction sextupole magnets. This paper presents the design and construction of a sextupole magnet prototype for SPS-II project. Magnet prototype was designed with the magnetic field gradient of 2,030 T/m2 and includes functions of skew-quadrupole, horizontal and vertical correctors. The magnetic core is made of S10C low-carbon steel. A prototype of sextupole magnet has been constructed. All dimensional tolerances are within the range of ±20 µm.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS076  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THPTS100 Measurements of Decay and Snapback in Nb3Sn Accelerator Magnets at Fermilab dipole, injection, quadrupole, luminosity 4342
 
  • G. Velev, G. Ambrosio, G. Chlachidze, J. DiMarco, S. Stoynev, T. Strauss
    Fermilab, Batavia, Illinois, USA
  
  Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
In recent years, Fermilab has been executing an inten-sive R&D program on Nb3Sn accelerator magnets. This program has included dipole and quadrupole models and demonstrators for various programs and projects, including the HL-LHC accelerator upgrade project. A systematic study of the field decay and snapback during the injection portion of a simulated accelerator cycle was executed at the Fermilab Magnet Test Facility. This paper summarizes the recent measurements of the MQXFS1 short quadrupole model and discusses the results of some previously measured Nb3Sn magnets at CERN 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS100  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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FRXXPLM2 Magnet Design for Siam Photon Source II photon, quadrupole, vacuum, multipole 4361
 
  • P. Sunwong, P. Klysubun, T. Phimsen, S. Prawanta, P. Sudmuang
    SLRI, Nakhon Ratchasima, Thailand
  
  Siam Photon Source II project has been approved and detailed technical design of the accelerator system is currently in progress. The Double Triple Bend Achromat (DTBA) lattice is implemented in the storage ring design for low emittance and more space for insertion devices. Magnets with moderate to high field requirements have been designed, including combined function magnet with the field gradient of 27.1 T/m, quadrupole magnets with the field gradient up to 60 T/m and multifunction sextupole magnets. This work presents the magnet requirement and specification, design concept, recent simulation results and analysis of the magnetic field quality. A plan for prototype development is also discussed.  
slides icon Slides FRXXPLM2 [1.475 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-FRXXPLM2  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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